Sens. Jeanne Shaheen, D-N.H., and Pat Toomey, R-Pa., talk to reporters about the farm bill at the U.S. Capitol in June. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

A shopper surveys the produce at Pacifica Farmers Market in Pacifica, Calif., in 2011. AP hide caption

itoggle caption AP

Grandpa Traub — corn former and millionaire. Chana Joffe-Walt/NPR hide caption

itoggle caption Chana Joffe-Walt/NPR

Sweet potato evangelist Maria Isabel Andrade from the International Potato Center drives around Mozambique in her orange Toyota Land Cruiser. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

Potatoes come in all colors, like these Red Erik, Snowball, Cariboo, Purple Peruvian, Caribe and French Red varieties. David Cavagnaro/Corbis hide caption

itoggle caption David Cavagnaro/Corbis

These piglets on the Hardin farm in Danville, Ind., are going to cost more to feed than they will fetch at market. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

A tomato expert recommends planting seedlings in rich soil with lots of organic matter and a steady slow-release fertilizer. iStockphoto.com hide caption

itoggle caption iStockphoto.com
iStockphoto.com

A clampdown on contamination in growing fields has pushed out wildlife and destroyed habitats. Adam Cole/NPR hide caption

itoggle caption Adam Cole/NPR